There are many methods known for controlling pests, such as bugs, insects and rodents, by distributing pesticide throughout a building. Liquid pesticide is commonly sprayed along most baseboards and other exposed areas of a house or office building, both on the inside and outside of the building. The depositing and spraying of liquid or solid pesticides has certain inherent dangers. Hazardous materials may inadvertently be contacted by infants or pets, or possibly contaminate food supplies. Thus, the application of pesticides in a building can create a health hazard. In addition, despite efforts to spray liquid or aerosol pesticide into cracks and crevices in building walls and baseboards, the pesticide does not access the area in which most bugs and insects live, i.e., in the interstices of the walls.
In an effort to direct pesticide into areas commonly occupied by pests, numerous systems have been developed in which a distribution system is installed through the studs, joists, rafters, and built-ins of building during the construction phase. Examples of such systems are shown in Ramsey, U.S. Pat. No. 3,676,949 and Lundwall, U.S. Pat. No. 4,028,841.
An improved system for distributing pesticides throughout the walls of a building is set forth in my previous U.S. Pat. Nos. 4,944,110 and 5,231,796, the disclosures of which are incorporated herein by reference. These patents disclose a system in which lengths of flexible tubing having a plurality of spaced, tiny discharge orifices are distributed throughout the walls of a building during construction. Individual lengths of tubing are extended throughout every interior and exterior wall. Perforations in the tubing have conical discharge orifices, enabling rapid expansion of the pesticide as it exits the tube. Each of the tubes have an open end which terminates at a location on the exterior of the building. Thus, when a service person desired to inject pesticide into the tube, each tube would be serviced individually. First, pesticide would be injected into the tube, and then the line would be flushed or purged with a follow-up injection of nitrogen. Service personnel would then go through each line sequentially, first injecting pesticide, and then purging with nitrogen.
The necessity for injecting pesticides, and subsequent purging with nitrogen, through a large number of individual lines can cause a number of unforeseen problems. Depending on the size of the building, it may be necessary to conduct the injection/purging operation on a dozen, or perhaps many more, lines. Service technicians may skip one of the lines, or inadvertently inject one of the lines more than once, resulting in distribution of an excessive amount of pesticide in a single area. Furthermore, the opportunities of spilling of pesticide in the treatment of a large number of individual lines is increased. In addition, when individual lines are serviced with portable equipment, it is common not to use any measuring equipment to determine how much pesticide has been injected into a single port. Frequently, service personnel will simply estimate the amount of pesticide injected into a port by the amount of time the pesticide line has been connected to the port after the valve has been turned on. However, since the lines inside the house may vary significantly in length (depending upon how far away the line must travel before it gets to its desired wall location), measurement may be quite inaccurate.
In addition, in prior systems there was no way in which a service technician could determine whether or not the pesticide was actually reaching its intended destination within a building. If the interior lines had become crimped or plugged, there was no way for the technician to know that flow had become restricted.
In accordance with the present invention, sources of pesticide and compressed air or nitrogen are mounted on a vehicle. The vehicle may be a truck or a smaller cart which may be wheeled closer to the injection port in an exterior wall of the house. Separate lines for pesticide and compressed air extend from the sources to an injector gun. Valving associated with the injector gun permits selective injection of pesticide or purge gas. A flow meter and pressure gauge may be included on each line. If desired, a single line to the gun can be used, with pesticide and compressed air traversing the same line.
The injector gun mates with a single aperture in a manifold which is accessible from the exterior of the building. The manifold, which is located inside the exterior wall, has a plurality of nipples to which the flexible hoses which extend throughout the building are connected. To service the system, a technician attaches the gun to the manifold opening, and fills the manifold and lines with liquid pesticide while monitoring the pressure and flow meters. When the lines are filled to the desired degree, the valving is switched to permit purging of the lines with inert gas. The entire operation can be done without removing the injector gun from a single connection on the exterior of the house.
In a preferred embodiment, a computerized record of the servicing transactions is maintained on the vehicle. At the end of the service call, a computer will print out relevant information for the service call, such as the date and time of service, name of service technician, and quantity of pesticide distributed. The computer can also print out a billing for the service call which can be left at the building when the service has been completed.
In another embodiment of the invention, a coupling for lengths of distribution tubing is provided which creates an audible sound when a gas passes through the coupling. Preferably, the audible sound is that of a high-pitched whistle which is easily heard through a wall of the building. A technician can test the operability of the lines extending throughout the walls by attaching a source of compressed air to the single exterior port, and moving from room to room throughout the house to determine if the sound is heard in all of the rooms. If necessary, a listening device, such as a stethoscope, can be used to hear the noise emitted at the coupler.